128 MADREPORARIA. 
of short irregular processes, mammillate, lobate and nodulated, the longer being frequently bent 
and swollen at the tips. Their thickness is very variable; the largest are 2 cm. They all 
project irregularly from a solid mass, the surface of which is smooth, or when it runs in 
between the processes, smoothly convex. 
The calicles are slightly depressed on the tips of the processes ; on the smooth surface they 
are quite superficial, and of obscure outline, appearing as irregular star-like arrangements of 
pores. The wallsare thick and flat (except where on the processes they surge up as a delicate 
flaky reticulum), and covered with a delicate, crisp, almost filamentous tangle of frosted threads 
and echinulate granules. The septa continue this crisp surface-tissue into the calicle. The septal 
granules are hardly distinguishable from the wall tissue. The pali are inconspicuous, very 
variable in number, the four principals alone being well developed. As the columellar tangle and 
fusions of the septa are deep down, the interseptal loculi are conspicuous at the surface, hence 
the star-like appearance of the calicles. The fossa is deep and round, but may be obscured by 
a small tubercle rising from light skeletal threads. 
In the younger calicles there is an irregular circular trough between the pali and the septal 
granules ; this makes the calicles conspicuous. 
The colour of the unbleached coral is greyish white. The cross section of one of the processes 
shows a very loose trabecular system, with thin concentric bars. 
This may be the same kind as P. Great Barrier Reef 19: the growth-form is the same, and 
the differences in their respective calicles appear slight, but of course with such variable 
structures the value of the differences cannot be well estimated. The chief difference here 
seems to consist in the presence of very minute granulations on the surface of the flakes 
in this specimen. I describe the two separately because of this difference, and because they 
are from localities fairly wide apart, but the resemblance between their growth-forms is 
certainly remarkable. This is one of those cases in which it is best to remain on the safe 
side. It is easy enough—indeed, it saves trouble—to put the two together under one 
description ; but there is no evidence of their specific identity. 
The original explanate base of this coral can still be seen; there are several layers, 
one or the other forming a basal crust, 6 cm. by 4cm. Above this base the coral expands 
suddenly into a solid mass, from the top of which the processes rise, tending all to stream 
one way. 
a, Zool. Dept. 92. 12. 1. 360. 
118. Porites Great Barrier Reef (4925. (P. Queenslandie quinta et vicesima.) 
(CAL OWA ailees 7/8 IPL ZO: vies, Ik7e)) 
[Thursday Island, coll. W. Saville-Kent; British Museum. ] 
Description.—The corallum rises as a flat-topped column, thickening as it rises. From the 
flat top fresh columns rise in clusters, their flat tops fusing irregularly. The separate tiers of 
columns are 5 cm. high, and the living layer extends about the same distance. 
